Some 55% of global deforestation is caused by slash-and-burn agriculture. Logging accounts for 20% of global deforestation. Roads and infrastructure construction account for 15%, and cattle ranching accounts for 10%. (1997 NASA images) p. 205 (Mark Hertsgaard, Earth Odyssey: Around the World in Search of Our Environmental Future, Broadway Books, 12/98). Comments: Which definition of "deforestation" is being used here is not stated.

World Wide Fund for Nature says 10% of the world's tree species face extinction. The "World List of Threatened Trees" describes over 8,753 of the world's 80-100,000 tree species as endangered (Reuters, 8/25/98).

Some 9% of the world's tree species are at risk of extinction. (

UN Development Program, "World Resources 2000-2001: People and Ecosystems, The Fraying Web of Life", UNEP, 3/10/00).

A global map showing net flux of carbon from terrestrial ecosystems into the atmosphere in 1980 due to deforestation and agricultural expansion is in Ref. (87H1).

Efforts to save most of the world's rainforests are doomed to failure and should be abandoned, a group of European scientists said in a report in the New Scientist magazine. Scientists at the European Commission's Joint Research Center in Italy gave a bleak outlook. The research team of 12 experts in tropical forests said there was no hope of stopping deforestation by logging companies and farmers in major rainforest regions such as Indonesia and much of the Brazilian Amazon (Reuters, 10/28/98).

Net releases of carbon into the atmosphere in 1980 from tropical deforestation are tabulated in Ref. (87H1). Releases are listed by country and by forest type (closed, open, fallow). Total release is 1.66 Gt. C/ year, implying a deforestation rate of 3.32 Gt./ year of dry organic matter (87H1).

Ref. (80N1) argues that rainforest destruction is not caused by food shortages bought on by over-population, but land-clearing for cash (export) crops and cattle for first-world consumption.

See an extensive discussion of global destruction of rainforest in Ref. (80M1). Comments: This argument seems to be contradicted by some facts: 80% of tropical deforestation is for fuel wood (FAO data) (86M1). In addition, 250 million third-world residents rely on shifting cultivation on 3 million km2 of forestland (including fallow) (80S1, 80U1), and shifting cultivation is practiced on 20% of tropical moist forests (Sommer, 1976) (80U1).

During 1960-1990, developing countries lost 20% of their natural tropical forest cover (97S1).

Sub-Part [Aa1] ~ Forest Degradation ~ Cumulative Deforestation ~
The Global 2000 Report notes that current trends predict a 23% decline in growing stock in the world's forests during 1980-2000, and a decline in per-capita growing stock from 76.5 m3 in 1978 to 40 m3
in 2000 (82W1).

From 1850 to 1980, forest losses have been greatest in North Africa and the Middle East (-60%), South Asia (-43%) and China (-39%). Highest deforestation rates are in South America (-1.3%/ year) and Asia (-0.9%/ year) (p. 107 of (90W1)).

Since pre-agricultural times:

The world's forests have declined from 50 to 40 million km2;

Temperate forests have lost 32-35% of their original area (90W1);

Subtropical woody savannas and deciduous forests have lost 24-25%;

Old-growth tropical forests have lost 15-20%,

Tropical evergreen forests lost only 4-6% because they were inaccessible and were sparsely populated (90W1).

Just over 50% of the world's forests are in developing countries (p.107 of (90W1)). (la)

Since 1900, almost 50% of tropical rainforests have been eliminated (80N1).

Savannas, which some people believe to have been entirely converted from tropical forests, cover 15 million km2 (79S1). (la)

Some 3 million km2 of converted tropical forest were under cultivation by the late 1970s (79S1).

Climax Area of Tropical Moist Forest and Deforestation (Sommer, 1976) (86B1) (Col. 2 and 3 are in millions of km2)

A 1981 UN satellite study showed tropical moist forests in the world disappearing at 72,900 km2/ year. Other studies put the loss at 200,000 km2/ year (84B3).

The current (1970s?) loss rate of tropical rainforest is estimated at 110,000 km2/ year (1.2%/ year) (79M2).

FAO estimates of forest loss rates are 50,000-100,000 km2/ year in Latin America, 20,000 km2/ year in Africa, and 50,000 km2/ year in Asia. But these figures reflect neither the degradation of timber and other biological resources in the remaining forests nor the severe depletion of open woodlands and countryside vegetation occurring in most third-world countries (80S1).

FAO estimates in 1981 gave a global deforestation rate of 113,000 km2/ year during the 1970s (93M1). In 1990, FAO estimated 170,000 km2/ year (for 1970s?) (93M1).

The rate of tropical deforestation is 114,000 km2/ year (1980 FAO estimate) (p.101 of 90W1).

Reidar Persson's 1974 study estimated that 20,000 km2/ year is cleared in Africa, and 60,000 km2/ year in Latin America (77B1). For developing countries as a whole, 120,000 km2/ year of natural forests are being cleared and burned (Ref.11 and 12 of (77B1)).

Ref. (80J1) cites a NAS (Norman Myers) estimate that 245,000 km2
of tropical forests are converted to other uses yearly.

Current tropical-rainforest loss rate: 250,000 km2/ year (3.3%/ year) (80N1). Comments: Loss rates of this size are now considered to be too high.

Ref. (83S1) cites a 1980 report from the US National Academy of Science that indicates that the UN estimate of tropical-moist-forest loss rate of over 100,000 km2/ year is inaccurate. The US NAS estimates a loss rate of 210,000 km2/ year (83S1).

A 1982 FAO study estimated a tropical-forest loss rate of 113,000 km2/ year during the 1970s (____).

Sub-Part [Aa3] ~ Forest Degradation ~ Deforestation in the 1980s
~
In a sample of 143 countries, the FAO (1995a) estimates that natural forests declined in area by 1.84 million km2 between 1980-90, and other wooded land declined in area 0.95 million km2 (96N1).

The FAO (1995b) estimates that the global change of forest cover has caused a loss of 2.7 Gt. of biomass between 1980-90 (96N1).

Half of the tropical deforestation during the 1980s took place in 6 countries: Brazil, Indonesia, Dem. Republic of Congo, Mexico, Bolivia and Venezuela (98A1). Comments: "deforestation" is an ambiguous word. It could mean logging (a temporary change) or conversion to croplands (a permanent change).

About 80% of tropical "deforestation" is for fuel-wood (FAO data) (86M1). Comments: The wording here is bad. Firewood gathering is not deforestation by some definitions since the land is not converted to non-forest uses.

Tropical logging was degrading rainforests at 45,000 km2/ year around 1990 (91P1). But logging roads make forests more accessible, and this leads to fires and clearing by farmers and ranchers - the two leading direct causes of forest loss (91P1). Comments: The other direct cause of deforestation (urbanization) is also promoted by roads.

Globally, forests declined 130,000 km2/ year during the 1980s (Ref. 30 of (94P1)).

In 3/93 the UNFAO reduced its estimate of tropical deforestation for the 1980s to 154,000 km2/ year from 169,000 (93M1) (93U5). (17,500,000 km2 of tropical forests remain (93U5).)

For tropical regions as a whole, 113,000 km2/ year were cleared in the early 1980s, while 11,000 km2/ year of plantations were established (88P1).

Over 166,000 km2 of rain forests were completely and permanently cleared in 1990, as compared with 101,000 km2 in 1980 (91J1) (UNFAO estimate). In addition, 202,000 km2 were grossly disrupted in 1990 (91J1). This suggests that 1.5%/ year of the biome is being destroyed and 2.0%/ year is being heavily degraded (91J1).

The deforestation rate for Brazil's Amazon is between 17,000 and 80,000 km2/ year, making the global rate between 139,000 and 204,000 km2/ year (90W1). Comments: Ambiguous.

Global statistics for tropical deforestation range from 69,000 km2/ year in 1980 (Ref. 3 of (93S1)) to 100,000-165,000 km2/ year in the late 1980s (93S1).

Tropical rainforests are vanishing about 50% faster than previously estimated (202,000 km2/ year vs. 113,000 km2/ year) according to a World Resources Institute Report based on 1987 data (90H2).

The worldwide loss of both closed- and open tropical forests amounted to 204,000 km2 in 1987 (90W1). Comments: These high estimates might now be considered too high due to over-estimation of 1987 Brazilian losses. "Open" forests are typically those occupying dry areas such as savannas. They contain about a fourth as much biomass per unit-area as closed forests (See data in Chapter 3).

The tropical forest loss rate is 154,000 km2/ year (62,000 km2/ year in South America, 1.6%/ year in Southeast Asia, 1.5%/ year in Central America) (93A1). See details in the table below.

The present global rate of tropical forest clearing (depletion of forest cover to under 10%) is 154,000 km2/ year. In addition, an area of roughly equal size is disrupted but not cleared outright, through selective logging and shifting cultivation (Ref. 26 of (95D2)). Comments: Both are temporary changes - r they might be.

00R1) indicated that the number of publications on tropical deforestation has grown at such a rapid rate over the past 10 years that it has become difficult to 'keep up' with it (01F1).

Results of a study (

01F1) indicate that the world's tropical forests continue to be lost at about 86,000 km2/ year in the 1990's, vs. a loss of around 92,000 km2/ year during the 1980s. During the same period, the loss of closed forests dropped from 80,000 km2/ year in the 1980's to 71,000 km2/ year in the 1990's. With standard errors on these estimates at 15%, the reduction in deforestation rates between the two decades is not significant (01F1).

Forests are shrinking globally by 113,000 km2/ year (UNFAO's biannual State of the World's Forests report of 3/1/99) (Agence France-Presse, 3/2/99). Comments: Probably means converted to other uses.

FAO estimates that the rate of forest loss in developing countries decreased from 154,600 km2/ year during 1980-90 to 130,000 during 1990-95 ((97F1), p.18). More recent studies - notably in Indonesia and Brazil - suggest that this 130,000 figure under-estimates actual forest loss ((

Some e44% of the world's original temperate rainforest vanished by around 1990, leaving 230,000 km2 left (93D3). Comments: This suggests an original area of 523,000 km2. (la)

Of the original 310,000 km2 of temperate rainforests, 56% have been logged or cleared (92R2). Comments: This suggests that about 136,000 km2 remain. (la)

At least 55% of the world's coastal temperate rainforests have been logged or cleared for other uses, leaving 140,000 km2 (Ref. 7 of (94D2)). Comments: This suggests an original area of 255,000 km2
(la)

Thailand's mangrove forests declined from 3127 km2
in 1975 to 1689 in 1993 (Ref. 36 of (00P1)). Another estimate gives a loss rate of 57.2 km2/ year (Ref. 37 of (00P1)). Comments: Much of this went to aquaculture. (la)

During the Vietnamese War, herbicides and defoliants destroyed 1000 km2 of mangrove forest. By 1983, 2525 km2 of mangrove
forests remained in Vietnam - mainly second-growth plantations and bushes (00P1).

Sub Part [Aa8] ~ Forest Degradation ~ Plantations
~
No soil on Earth (especially tropical soils) can take the magnitude of depletion represented by plantations of fast-growing tree species (98M1). Comments: Tropical soils store the bulk of their nutrients in their living- and dead vegetation. Removal of timber, like removal of crops, like removal of grass (grazing of domestic animals), cannot be sustained without long periods (2-3 decades) for recovery of nutrients from deep in the sub-soils after 2-3 years of cropping, or 5-10 years of grazing.

A 1995 Central Bank of Chile report estimates that 1200 km2
of Chilean forest are destroyed each year. Of this, 600-900 km2
are replaced with tree plantations (97H2). (la)

Well over 50% of all tropical deforestation is due to slash-and-burn agriculture by displaced landless peasants ("shifted cultivators" - in contrast to "shifting cultivators" of tradition, who cause no long-term injury to forest ecosystems) (95M2).

The breakdown of shifting cultivation patterns is responsible for 70% of closed-forest clearing in tropical Africa, nearly 50% in tropical Asia, and 35% in tropical America (88P1) (FAO data). Comments: See table at top of "Deforestation in the 1980s" to get numbers.

Ref. (81B1) presents arguments to support the view that shifting cultivation produces a permanent degradation of biological productivity (81B1).

Ref. (56S1) argues that shifting cultivation does not deserve its bad name. Abandonment of the land after a time to permit the redevelopment of woody growth is a form of rotation whereby the soil is replenished by nutrients carried up from deep-rooted trees and shrubs to be spread on the ground as litter. Such land use is freed from the limitations of terrain on plowed fields. The method gives much better protection against soil erosion than does any plowing (56S1).

For many tropical areas of Africa, Latin America and Southeast Asia, no alternative food-production system to shifting cultivation has yet proven both biologically and economically workable (76E1). Comments: Rapid expansion of soybean croplands in Brazil would suggest that this is no longer true.

The two principal causes of deforestation today are land clearing for agriculture and wood gathering for fuel. A third cause - timber harvesting for direct- or industrial use - is far less significant on a global basis (76E1). Comments: Timber-harvesting in the tropics is expanding rapidly, so this statement may now be incorrect. Fuelwood gathering is not deforestation unless its rate greatly exceeds sustained yield.

Wong (1978) estimates that the rate of organic matter consumption in fires associated with shifting cultivation is 6 Gt./ year (86V1). In addition, 3 Gt./ year are consumed in permanent forest clearing (86V1). Seilers and Crutzen (1980) calculate that similar amounts of material are destroyed by shifting cultivation (86V1).

Forest farmers (shifting cultivators, smallholder agriculture, squatter colonization) totaled over 140 million people worldwide in the mid-1970s. They occupy 2 million km2 and convert 100,000 km2
of primary forest to permanent cultivation yearly - accounting for a loss of tropical forest biomass of over 1%/ year (80M2). Comments: Data above give 250 million people on 3 million km2 of forestland (including forest fallow) (80S1), (80U1).

Less than 10% of existing rainforests are growing on soils of the type that can support significant population densities. On the remaining 90%, shifting cultivation can support only 10 people/ km2, i.e. about 100 million people (84G1) (World Bank data). Ref.10 of Ref. (84G1) describes a successful procedure for using these poor tropical soils, but heavy, skilled applications of fertilizer and high crop prices are required. Though conditions vary widely, shifting cultivation can only support about 7 people/ km2
(76E1). Shifting cultivation can support 5-10 people/ km2 with a 20-year fallow period (Ref. 4 of (84P1)). Limitations of this nature can explain the demise of the old Mayan empire (56B1).

Shifting cultivation in tropical rainforest can be stable (1-3 years of cultivation followed by 10-30 years of fallow) only for population densities of under 8 people/ km2 (Ref. 14 of (82B2)).

Per-capita food production in Africa has declined over the past 20 years - a distinction shared by no other continent (76E1). Shifting cultivation with too short a fallow period is seen as a source of the problem (76E1). Comments: "Soil mining" as a result of too little use of chemical and/or organic fertilizers is a more likely cause.

After removal of rainforest forest cover in western Nigeria, maize yields drop from 500 to 150 tonnes/ km2/ year after 2 years, and to 50 tonnes/ km2/ year after 4 years (Refs. 24, 37 of (88L4)).

About 40% of the forestland of Bangladesh is being rapidly depleted by illicit timbering and shifting cultivation (80R3).

[Ab4b] ~ Shifting Cultivation - Asian Sub-Continent -India ~
Average fallow period for shifting cultivation in India = 4.3-5.9 years (91J2). Tropical rainforest area affected = 94,700 km2
(4.2 million families) (FAO, 1981 Landsat data) (Area burned annually is much less.). This area is broken down among 11 Indian states in Ref. (91J2).

The latest (satellite) survey also indicated that more northeastern India forests are put to shifting cultivation than abandoned for post-shifting cultivation regeneration annually. The survey showed that 63,000 km2 in northeastern India are affected. Out of the 64% forest cover in the region, 35% cover is good (dense) and the remaining 29% comprises post-shifting cultivation open/ degraded secondary successional forests that require protection (95K1).

Sub-Part [Ab6] ~ Shifting Cultivation ~ Latin America
~
Tropical rainforests in Latin America are cleared for temporary farming (shifting cultivation) at rates of 50-100,000 km2/ year (76E1), (73A1) (FAO study). Comments: Only about a third of this is clearing of undisturbed forest.

[Ab6a] ~ Shifting Cultivation ~ Latin America - Brazil ~
The land of Belim (in Brazil east of Para River, north of Guama River) (21,000 km2) has been entirely cleared of forest, so the fallow period for shifting cultivation is under 5 years (56G1). Under such conditions, soil deteriorates rapidly (56G1).

About 10% of the Brazilian tropical forest area affected by shifting cultivation has been reforested (Ref. 20 of (78B1)) (UN data).

Some 22 million Indonesians are small-scale slash/ burn cultivators engaged in long-term rotational farming, a practice that has been sustainable for thousands of years (98R1). Comments: Sustainability is doubtful. The carrying capacity of tropical rainforest for shifting cultivation is around 10 people/ km2, and it is not clear that Indonesia has 2.2 million km2 of rainforest.

Sub Part [Ac1] ~ Conversions to Other Uses - Global
~
A global average of 73,000 km2 of trees were lost (logged?) annually between 2000-2005, down from an average of 89,000 km2
per year during the 1990s. Critics argue that, in highlighting global net losses, the FAO report glosses over the losses from the world's most important tropical forests. Comments: This probably means that the decrease in tropical forest area and standing timber volumes is being counteracted somewhat by increases in temperate forest area, forest plantations and standing timber volumes (

Each year about 130,000 km2 of the world's
forests are lost due to deforestation, but the rate of net forest loss is slowing down, thanks to new planting (plantations) and natural expansion of existing forests, FAO announced (

Deforestation, mainly due to conversion of forestland to agricultural land, continues at a rate of 13 million hectares (130,000 km2) per year (05F1).
Comments: "agricultural" might include grazing lands.

According to a remote sensing survey (01F1), during the last decade, most conversion of forests were into agriculture, pastures and shifting agriculture. Comments: Another possible mode of conversion is to urban developments.

A good part of the world's 38,000 km2/ year net new cropland over the period to 2030 will probably come from forest conversion. A high proportion will have steep slopes and will be in zones with high rainfall, so the water erosion risk will be high unless suitable management techniques are adopted (00F1).

Over the millennia, 15-20 million km2 of temperate forest have been converted to arable lands and grasslands (grazing lands?). This area is comparable to the total area now in temperate grasslands and non-tropical croplands (Ref. 2 of (79S1)). Other references cited in Ref. (79S1) estimate 8 million km2 converted to temperate grasslands and non-tropical croplands. Comments: Much temperate grassland reflects the fact that trees can't grow in areas with rainfall less than about 20"/ year, so the 15-20 million figure seems suspect.

Seiler and Crutzen (1980) estimate that forests are converted to grazing lands at 60,000 km2/ year, mostly in Latin America (86V1). Houghton et al (1983) estimate a similar value (86V1). 2 million km2
of forest lands have been converted to grazing land in the past 30 years; 7 million km2 during human history (86V1).

A review of the literature on the effects of livestock grazing on forest health is given in a 5/9/95 memo "Livestock Grazing is a Major Cause of Forest Health Problems" to Regional Forester Charles Cartwright from Southwest Center for biological Diversity, P.O. Box 742, Silver City NM 88062 (505-538-0961) (swcbd@igc.apc.org) and Southwest Forest Alliance, P.O. Box 9314, Santa Fe NM 87504 (505-983-4609) 81 references, 6 pages. Comments: The essence of this review is that grazing in forests favors the growth of shrubs and woody plants over grass, and this results in greatly enhanced fire danger to forests, and numerous other problems for trees. The issue is not about conversion of forests to grazing lands, but the use of forests for grazing.

Some 46% of the potential area of temperate broadleaf and mixed forests is now agricultural land, accounting for 24% of total agricultural land. 43% of the potential area of tropical deciduous forest (similar to rainforest) has been converted to agriculture, accounting for 10% of total agricultural land ((00W1), p. 66).

About 40% of tropical forests have been removed - chiefly to make soil and nutrients available for agriculture (80R1).

Cleared tropical forestland can sustain 4 cows/ km2
on average, and the average lifetime of a ranch is 2-7 years before it must be abandoned due to weed-growth, erosion and nutrient loss (84G1). After 7-10 years of beef cattle grazing, torrential rains and overgrazing turn the former rainforest's nutrient-poor soil into eroded wastelands (Ref. 8 of (83N1)). Comments:
Others have estimated 5-10 years as the average lifetime on a cattle ranch on tropical rainforest soils (2-3 years for cultivation).

Sub-Part [Ac2] ~ Conversions to Other Uses - Africa
~
The rate of forest loss in Africa is 0.6%/ year; losses in the world at 0.18%/ year. At this pace, Uganda's forests will be gone in 50 years time. Population pressure and poverty are the underlying causes. With 7.1 births per woman, Uganda has the second highest fertility rate in the world. By 2050, Uganda's population will be 130 million, five times the current number. 97% of the population of Uganda uses charcoal and firewood for cooking. The number of people building houses, farming and grazing their livestock in Uganda's
protected forests went up from 180,000 to 220,000 between 2005 and 2006. ("Uganda: Forests in Danger," New Vision Online, 3/27/07.)

Madagascar's

traditional slash and burn agriculture is called "tavy." It involves converting tropical rainforests into rice fields; thereby exhausting the soil and leaving only scrub vegetation, alien grasses, eroded hillsides, and the constant threat of landslides. Forestland is freely available for clearing, so there is no incentive to manage it conservatively (07R1). (SU2)

Forested land in Sub-Saharan Africa was converted to agricultural uses at increasing rates over 1981-90, and such changes accounted for 25% of the changes in forest cover during that period (FAO data) (95M3).

Logging roads in Central Africa make forests accessible to farmers (shifting cultivators) who eliminate the remaining trees and, in a few years, destroy soil productivity (94C2).

[Ac2a] ~ Conversions to Other Uses - Africa - Morocco ~
Scrub environments in Morocco are expanding at the expense of forestland due to grazing (60M1).

Sub-Part [Ac3] ~ Conversions to Other Uses - South America
~
The Amazon rain forest is disappearing because of a growing appetite for farmland. About 10,000 square miles (26,000 km2) vanished during the 12 months ending 8/1/02, vs. 7,000 square miles (18,100 km2) over the same period a year earlier. The advance of agricultural and pastureland and the ongoing paving of roads are the main reasons for the destruction. Cattle ranchers and farmers have been pushing into the Mato Grosso and southern Para state. Brazil aims at paving 4,000 miles of dirt roads through the Amazon forest. This is pending reviews, but a third of the work has been completed ("

[Ac3a] ~ Conversions to Other Uses - South America -Brazil ~
In Brazil, by 1980 72+% of the conversion of forestland detected by satellite was for cattle pastures. After 1990, subsidized ranches caused 4 times as much deforestation as non-subsidized ranches did, even though 25% of the pasture was already abandoned because the forest soil could not support the land use. By 1988 the fiscal cost to Brazil of all of its 470 subsidized ranches was $2.5 billion (98A2).

All of Brazil's grasslands may be anthropogenic
(Ref. 22 of (79S1)).

By the late 1970s, 15,000 km2 of pasture had been established in the Brazilian Amazon (88P1).

Only 2% of Amazon basin soils are permanently cultivable
(84G1).

The average life of a Brazilian cattle ranch is 2-7 years before it must be abandoned due to soil deterioration (84G1).

In 1986 virtually all Amazonian ranches established prior to 1978 had been abandoned (86L1).

By 1980, ranching accounted for over 72% of Brazil's
forest clearing. The economic value of beef produced covered 55% of government subsidies for ranching. Total financial loss: $2.9 billion (88R2).

In Brazil, by 1980, 72% of forest conversions
detected by satellite were due to cattle pasture. After 1990, 4 times as much deforestation came from subsidized ranches as from non-subsidized ranches, and about 25% of the pasture was already abandoned (98A1).

More than 12% of the 5.2 million km2 of Brazilian Amazon forest has been deforested and converted to crop- and pastureland. The Brazilian Space Research Institute (INPE) gives the following data for area cut and burned: 11,000 km2 in 1992; 15,000 in 1994; 29,000 in 1995; 18,000 in 1996. (Preliminary analyses give a 1997 rate comparable to 1994.) (D. Nepsted, C.J. Tucker, US Global Change Seminar, Washington DC, 3/30/98).

[Ac3b] ~ Conversions to Other Uses - South America -Bolivia (Forest inventory: 668,000 km2 (90W1))
~
Bolivia's forest cover is converted to livestock grazing
at 3000 km2/ year (p. 357 of Ref. (91J1)). Comments: The meat is usually exported to developed nations, so Central American beef consumption is dropping. Comments: After 7-10 years, tropical grasslands used for grazing must be abandoned for several decades to allow the soil to recover its productivity.

[Ac3c] ~ Conversions to Other Uses - South America -Colombia ~
Colombia, according to Colombian environmentalists, is converting forest to pasture at a rate of 4000-6000 km2/ year (LanceOlsen@aol.com 10/18/99).

In Colombia, 4000 km2/ year of tree- and brush-cover are cleared for forage and cropland (91J1). Comments: The rate is probably far greater by now (2007).

Colombia's settlers cut down 4000 km2/ year in converting land to fields (croplands) and pastures (93W5). This situation has been largely a result of Colombia's attempts to develop their market economy with cash crops for export. These export crops are grown on the better lands by large landholders, thus marginalizing small farmers who must become "settlers" (93W5).

Colombian forests are being converted to illegal drug crops at a rate of over 5600 km2/ year (Pittsburgh Post Gazette, 5/10/97).

More than 405 km2/ year are deforested in Colombia
to grow coca, marijuana, and opium poppies (93W5). 73% of the Andes, an area vital to the conservation of Colombia's water supply, have been deforested as a result of migration and drug cultivation (93W5).

[Ac3d] ~ Conversions to Other Uses - South America - Peru ~

Since the 1950s, Peru cleared 85,000 km2 of Amazon forest for cattle grazing and cropland. Most of this is now abandoned. Today the area produces 9000 tons of meat/ year - 5.7% of Peru's consumption (Ref. 27 of (95D1)).

[Ac3e] ~ Conversions to Other Uses - South America -Venezuela ~

About 50,000 landless peasant families (250,000 people??) have been clearing forest at 850 km2/ year (Ref. 8 of (84P1)).

Almost 75% of Venezuelan forest loss registered during the 1980s can be directly related to expansion of agriculture (95C1).

Deforestation rates in Central America (3.2%/ year) are motivated mostly by conversion to cattle ranching (Nations and Komer, 1983). Much of the impetus is to provide low-grade beef for the US fast-food industry (Parsons, 1976) (86B1). Comments: Other data indicate that no more than 40% of Central America deforestation is attributable to grazing-land creation (84P1).

In Indonesia, 66,000 km2 of forest was burned to establish palm oil plantations - 22,000 in the past 5 years. (

00P1)

The Indonesian government plans to clear 6000 km2 of tropical forest to croplands to grow soybeans (200,000 km2 of prime soybean lands lie non-cropped in the US and Argentina.) (92A1).

[Ac5b] ~ Conversions to Other Uses - Southeast Asia - Java ~

Less than 2% of the soils of the Kalimantan Forest
(Indonesian Borneo) are believed to be permanently cultivable, yet 4 million people are being settled there as a part of a massive Javanese resettlement program (84G1).

During 1961-1985, 100,000 km2 of Thailand's
forestland were converted to agricultural land (80% of total forest encroachment) (88P4). (la)

Sub Part [Ac6] ~ Conversions to Other Uses - Latin America
~
The amount of land cleared in Brazil's Amazon jungle rose sharply again in 2003-04. Brazil's Environment Ministry said, on 5/18/05, that destruction of the world's largest tropical forest rose to 10,088 miles2
(26,130 km2) in 2003-2004 - from 9,496 miles2 (24,597 km2) in 2002-03. As Brazil grabs an ever-larger slice of global agricultural trade, the expansion of soy growing and cattle farming into the Amazon basin may become impossible to stop. The worst year for Amazon destruction was 1994-95, when 11,216 miles2 (29,050 km2) were cleared. The 2003-04 figure is the second largest amount of land cleared. The World Wildlife Fund said that 17.3% of the Amazon Basin has been destroyed (Comments:
Does "destroyed" meaning converted to agriculture, grazing, and/ or urban developments?). Nearly half the total deforestation took place in Brazil's Mato Grosso state, whose Gov. Blairo Maggi's farming operations are the world's single largest soy producer. Soy is Brazil's biggest farm export. Sales were about $10 billion in 2004 (

Axel Bugge, Reuters News Service http://www.reuters.com/ 5/19/05).

Soy production has overtaken logging and cattle ranching as the main source of Amazon rainforest destruction. In the past 3 years, nearly 27,000 square miles (70,000 km2) of rainforest have been destroyed, most of it illegally. Much of the rainforest acreage was sold to soy producers, financed by Cargill. Brazil has become the world's leading exporter of soy

("Eating the Amazon: the Fight to Curb Corporate Destruction," The Independent, 7/17/06).

During 1970-90, Latin Americans converted over 200,000 km2
of tropical moist forest to cattle pasture (100,000 in the Brazilian Amazon, 15,000 in the Colombian Amazon, and 5000 in the Peruvian Amazon) (91D1). (la)

Sub Part [Ac7] ~ Conversions to Other Uses - Oceania
~
Over 50% of the 300-mile-long New Caledonia and 1/3 of 18,000-km2Fiji Islands (South Pacific) were converted to pasture
by around 1990 (91J1). (la)

Sub Part [Ac8] ~ Conversions to Other Uses - Scotland
~
For over 150 years, no new trees have grown to maturity because of intense grazing pressures from an increasing deer population. Thus only old trees inhabit Scotland's few Caledonia Forest remnants (93W3).

Sub Part [Ac9] ~ Conversions to Other Uses - US ~
0.5 million of the 5 million acres of US forest cut annually (2025 out of 20,250 km2/ year) are converted to urban- or agricultural use (Forest Watch, 7/91).

A 1988 USDA study estimates that 100,000 km2 of timberland in the US South have high or medium potential for conversion to cropland over the next 35 years (99N1). (Note: This is also in Topsoil Loss Review.)

During 1962-70, 12,000 km2 of former agricultural land was converted to forest in the US mid-Atlantic states, while 30,000 km2 of forest was cleared, largely for farming, in the US South (76S1).

During 1950-72, 130 km2 of pinion-juniper forestlands were cleared by "chaining" to create grazing lands (Ref. 11 of (84R1)). Comments: This would normally be in the arid grasslands of the US West.

The Freemont cottonwood communities once covered 1-2% of the US southwest. Today they cover under 0.01% of New Mexico. Livestock grazing is blamed (91J1). Livestock grazing is also a major factor in the decline of the plains cottonwood along the Missouri River in Montana (p. 54 of Ref. (91J1)).

On US western public lands, most riparian groves have been virtually eliminated by over-grazing, grazing-induced flooding, logging-induced flooding, logging, dams and developments (p. 54 of Ref. (91J1)).
Comments: A lot more material on riparian habitats is in the grazing lands degradation Review.

Some 94% of California's interior broadleaf woodlands have been significantly damaged or destroyed, largely by livestock (p. 53 of Ref. (91J1)).

Some 170,000 km2 of US forestlands could be converted to prime farmland (82W1).

Over 2 billion people depend directly on biomass fuels as their primary or sole source of energy (pp. 289-308 of Ref. (96I1)).

By 2010, 2.3-2.4 billion m3/ year of fuelwood and charcoal will be available (96N1). However wood fuel demand by 2010 is forecast to be 2.4 - 4.3 billion m3/ year (

00M1).

Three billion people depend on fuel-wood for almost all their household energy. About 1.5 billion of these people cannot obtain fuel-wood without over-cutting tree stocks. This total is expected to rise to 2.5 billion by 2010 (96M2).

Over 1.5 billion people depend almost entirely on wood for cooking and heating. In these nations, fuel-wood accounts for 90% of total wood consumption (79S3).

About 50% of all timber cut in the world is for cooking and heating (75E2).

Nearly 1.2 billion people in developing countries meet their fuel-wood needs by cutting wood faster than it was being replaced (84P1) (88P1) (FAO 1980 data). Comments: Population growth in developing nations suggests that this number is now far larger.

Wood fuels account for over 50% of biomass energy in developing countries, and if China is excluded (where agricultural residues are a particularly important fuel) they account for about 2/3 (96I1).

About 100 million people (50% in tropical Africa) could not meet minimum wood needs, even by over-cutting local woodlands. The number of people in 2000 lacking wood, or over-cutting, will double to 2.4 billion (84P1) (88P1) (FAO projection). Comments: Firewood productivity, like pulpwood, is optimized by cutting wood on rotations of about 35 years. So as population pressures increase, rotation periods decrease, decreasing yields - which decreases rotation periods even further, etc.

Ref. (88P1) tabulates the share of total energy provided by wood in selected countries in the early 1980s.

The average person who depends on firewood burns as much as 1 tonne/ year (76E1). When wood is used for cooking, 1-2 tonnes/ year/ person is required (78B1). 2/3 of the world's people use wood to cook food (Orr, 1946) (56G2).

The UN FAO estimates that 1 tonne of dung, used as fuel in place of firewood, means the loss of 50 kg. of food grain. So the 400 million tonnes of dung burned yearly in parts of Asia, the near East and Africa could be costing 20 million tonnes of grain/ year (78M1).

In traditional charcoal making, 50% of primary wood energy is lost. So every villager who moves to the city, and thereby switches from wood to charcoal becomes, in energy terms, two people (Ref. 24 of (88P1)).

- Tropical Nations ~
About 70% of wood harvested in tropical countries is used locally, mainly for fuel (90R1).

At least 80% of wood harvested in tropical countries (825 million m3) is used for firewood and charcoal (80U1).

Current wood removal in the tropics is 85% for fuel-wood (80R1). 80% of tropical deforestation is for fuel-wood (86M1) (FAO data). Comments:
The huge growth of wood exports to Japan etc. from tropical countries in recent years suggests that percentage of wood consumed locally may be declining rapidly. The more recent data may be more reliable.

Wood accounts for over 74% of Kenya's energy consumption (81S1).
Firewood demand is rising at up to 2.5%/ year (81S1) (1978 the Ministry of Natural Resources estimate).

Charcoal sources for Nairobi have moved to slopes of Mt. Kenya, over 125 miles away (87E2).

A ring of deforestation created by fuel-wood demand, spreads out 120 miles from Khartoum, and 180 miles from Nairobi (90H3).

[Ad3c] ~ Firewood/Charcoal Production- Africa - Senegal ~

A few years ago, 30 woman-days/ year were required to gather fuel-wood for a family. Today 300 woman-days/ year are required (81F1).

[Ad3d] ~ Firewood/Charcoal Production- Africa - Somalia ~

Fuel-wood sources for Mogadishu are 300 miles to the south (87E2).

[Ad3e] ~ Firewood/Charcoal Production- Africa - Sudan ~

Rising charcoal consumption in the Sudanese capital, Khartoum, has caused the area of charcoal production to shift to the south by an average of 15-20 km/ year. Charcoal supplies for Khartoum now come from as far as 400 km. away (97D1).

[Ad3f] ~ Firewood/Charcoal Production- Africa - Upper Volta ~

In Ouagadougou (the capitol of Upper Volta), the average family spends over 25% of its income on firewood (75E2).

A circle of trees 128 km. in diameter has been stripped for firewood in Ouagadougou (the capitol of Upper Volta), (80R2). (Ref. (76E1) says 140 km. in diameter.)

In many areas of Himachal Pradesh, Uttar Pradesh, Assam, Jammu and Kashmir, fire-wood is beyond the reach of village populations, so dung is burned instead (75E1). Comments: Dung-burning depletes soil nutrients, perpetuating the downward spiral of basic life-support systems.

In Kerala, one of the most densely inhabited states of India, a study in 1998 estimated that about 83% of the wood was from homesteads, 10% from estates and only about 7% from forest areas, when 26.6% of Kerala is under forest cover. Trees outside forests met 90% of the fuelwood requirements of Kerala (01F1).

[Ad4c] ~ Firewood/ Charcoal Production- Asian Sub-Continent - Nepal ~

Ref. (84E1) reports that the Khumbu Valley (Nepal) has been deforested over the past three decades due to fire-wood gathering. 95% of Nepal's felled trees wind up in stoves (87K1).

A Nepalese Agency, New Era, found that people took 5.2-6.3 hours to bring a load of wood from the forest. Ten years ago this time was 4.1-4.6 hours (87S2).

In the late 1960s, a UN forestry team found live tree branches, shrubs, seedlings and grasses were cut for fuel. Also many hillsides were raked free of all leaves, litter and burnable grasses. UN experts cited raking as one of the principle causes of soil erosion in Korea (76E1).

Sub-Part [Ad7] ~ Firewood/Charcoal Production

- US ~
A 1981 national survey found that 17 million of 79 million US households relied on wood for part of their heating fuel. Of these, 6.5 million relied on wood exclusively (84B2).

About 20% of forest harvest is used for fuel-wood (Ref. 30 of Ref. (91M1)).

Sub-Part [Ae1] ~ Urbanization of Forest Land - Global
~
The rate of conversion of forestland to urban uses is estimated to be about 400,000 km2/ decade, based on an analysis in a companion document to this review of deforestation ("Topsoil Loss - Causes, Effects and Implications"). This analysis concludes that global forest loss (and grazing-land loss) to urbanization is about 1%/ decade. For lack of better information, it seems reasonable to assume that this rate applies equally well to both tropical- and temperate forests. This assumption may be suspect because temperate urbanization is primarily economic-growth-driven, while tropical urbanization is primarily population-growth-driven.

Over the past 15 years the number of trees in the US has declined by 30%, while the space covered by solid surfaces has risen by 20% ("City Improvement: Planting Trees", Christian Science Monitor, 4/16/03).
Comments: Forest area may be better than number of trees.

0.5 million of the 5 million acres of US forest cut annually (2025 out of 20,250 km2/ year) are converted to urban- or agricultural use (Forest Watch, 7/91).

Estimated loss of US forestland to urbanization of all forms and to other non-timber uses over the next 5 decades is 40,000 km2
(76S1). Comments: Another estimate: loss of 140,000 km2 of US commercial timberland over the next 5 decades (81W1) (Section (3-D)).

Rapid population growth in the US between 1890-1940 did not decrease US forest cover, since urbanization trends were far more rapid than population growth. During this 50-year period many rural areas actually lost population, and most Eastern Forests actually grew back from denuded mountains (see the Weeks Act of 1911 at http://www.lib.duke.edu/forest/usfscoll/policy/Agency_Organization/NF_System /weeks_law/).

[Ae5b] ~ Urbanization of forest land - Southern US ~

A comprehensive Southern Forest Resource Assessment (SFRA) from the federal government concludes that suburban sprawl is the biggest threat to southern US forests. The multi-agency, multi-year study of southern forests, headed up by the US Forest Service, concluded that remaining southern forests are healthy and being sustainably managed, but did flag continued urban growth as a threat to long term sustainability. The report marks the end of one of the most comprehensive and complex studies of forests ever completed in the US (02U2).

A new report by the USFS says urban growth is the main cause of forest loss in the South. Between 1982-97, developed land in the South increased by 45%, representing 12 million acres (49,000 km2) of forest lost to development. In Georgia, where the population has increased 230% since 1952, developed land increased by 67% from 1982-97 (02U2).

A US Forest Service study forecasted that, over the next 4 decades, the US South would lose more than 30 million acres of prime forestland to urban development. Much of this urbanization will be in the Appalachian Mountains and the Florida Panhandle (01U1).

Wear (1998) (in (99N1)) estimates that 20-25,000 km2
of forestland in the US South will be urbanized by 2030.